What is Rehydration

Rehydration is the replacement of body fluids and salts and minerals (electrolytes) that are lost during dehydration. Dehydration is when there is not enough fluid or water in the body.

This happens when you lose more fluids than you take in. People who are age 65 or older have a higher risk of dehydration than younger adults. Common causes of dehydration include:

• Vomiting.
• Diarrhea.
• Excessive sweating, such as from heat exposure or exercise.
• Taking medicines that cause the body to lose excess fluid (diuretics).
• Impaired kidney function.
• Not drinking enough fluid.
• Certain illnesses or infections.
• Certain poorly controlled long-term (chronic) illnesses, such as diabetes, heart disease, and kidney disease.

Symptoms of mild dehydration may include thirst, dry lips and mouth, dry skin, and dizziness. Symptoms of severe dehydration may include increased heart rate, confusion, fainting, and not urinating.

You can rehydrate by drinking certain fluids or getting fluids through an IV tube, as told by your health care provider.

What are the risks?

Generally, rehydration is safe. However, one problem that can happen is taking in too much fluid (overhydration). This is rare. If overhydration happens, it can cause an electrolyte imbalance, kidney failure, fluid in the lungs, or a decrease in salt (sodium) levels in the body.

How to rehydrate

Follow instructions from your health care provider for rehydration. The kind of fluid you should drink and the amount you should drink depend on your condition.

• If directed by your health care provider, drink an oral rehydration solution (ORS). This is a drink designed to treat dehydration that is found in pharmacies and retail stores.
  • Make an ORS by following instructions on the package.
  • Start by drinking small amounts, about ½ cup (120 mL) every 5–10 minutes.
  • Slowly increase how much you drink until you have taken the amount recommended by your health care provider.
• Drink enough clear fluids to keep your urine clear or pale yellow. If you were instructed to drink an ORS, finish the ORS first, then start slowly drinking other clear fluids. Drink fluids such as:
  • Water. Do not drink only water. Doing that can lead to having too little sodium in your body (hyponatremia).
  • Ice chips.
  • Fruit juice that you have added water to (diluted juice).
  • Low-calorie sports drinks.
• If you are severely dehydrated, your health care provider may recommend that you receive fluids through an IV tube in the hospital.
• Do not take sodium tablets. Doing that can lead to the condition of having too much sodium in your body (hypernatremia).

Eating while you rehydrate

Follow instructions from your health care provider about what to eat while you rehydrate. Your health care provider may recommend that you slowly begin eating regular foods in small amounts.

• Eat foods that contain a healthy balance of electrolytes, such as bananas, oranges, potatoes, tomatoes, and spinach.
• Avoid foods that are greasy or contain a lot of fat or sugar.

In some cases, you may get nutrition through a feeding tube that is passed through your nose and into your stomach (nasogastric tube, or NG tube). This may be done if you have uncontrolled vomiting or diarrhea.

Beverages to avoid

Certain beverages may make dehydration worse. While you rehydrate, avoid:

• Alcohol.
• Caffeine.
• Drinks that contain a lot of sugar. These include:
  • High-calorie sports drinks.
  • Fruit juice that is not diluted.
  • Soda.

Check nutrition labels to see how much sugar or caffeine a beverage contains.

Signs of dehydration recovery

You may be recovering from dehydration if:

• You urinate more often than you did before you started rehydrating.
• Your urine is clear or pale yellow.
• Your energy level improves.
• You vomit less frequently.
• You have diarrhea less frequently.
• Your appetite improves or returns to normal.
• You feel less dizzy or less light-headed.
• Your skin tone and color start to look more normal.

Contact a health care provider if:

• You continue to have symptoms of mild dehydration, such as:
  • Thirst.
  • Dry lips.
  • Slightly dry mouth.
  • Dry, warm skin.
  • Dizziness.
• You continue to vomit or have diarrhea.

Get help right away if:

• You have symptoms of dehydration that get worse.
• You feel:
  • Confused.
  • Weak.
  • Like you are going to faint.
• You have not urinated in 6–8 hours.
• You have very dark urine.
• You have trouble breathing.
• Your heart rate while sitting still is over 100 beats a minute.
• You cannot drink fluids without vomiting.
• You have vomiting or diarrhea that:
  • Gets worse.
  • Does not go away.
• You have a fever.